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Weird. The key physics you should learn is that Niven’s Ringworld would require a material so strong we can’t even theorize about it. A Ringworld around our Su
by jmyeet 4y ago
Weird. The key physics you should learn is that Niven’s Ringworld would require a material so strong we can’t even theorize about it.
A Ringworld around our Sun at Earth’s distance with Earthlike gravity would rotate at (IIRC) 1.5 million kmh. The centrifugal forces would tear our apart.
A Dyson Swarm remains the most promising megastructure for creating efficient living area (per unit mass).
- nosianu 4y agoIt's also terrible for failure modes. Planets are independent of one another, this ring is one fragile entity. The largest destruction of life by a single unfortunate event in the entire universe made possible by one design decision. We know it's not indestructible (and can't be unless it's a fantasy novel with "magic"), I only read the first book and there were two large holes even in the tiny section they explored. Whatever happens to that hole in the ring that they find when they first encounter and land - crash - on the ring? Air is constantly lost through it. Not the one with the ultra-high "mountain" near where they crashed, the other one further along their route with the weather pattern caused by this air-loss storm. How is that sustainable - given the ultra-long time horizon, surely billions of years, that such a structure should be able to support life for (if a planet can do that much)?
- geon 4y agoThe lost air through the hole was not sustainable. The entire ring had fallen into disrepair. That was a major plot point. The terrible failure mode was typical for the extreme arrogance of the ringworld engineers.
- public_defender 4y agoThey blow up an orbital ring structure in Consider Phlebas and it definitely leaves one wondering who thought it was a good idea to build it in the first place.
- greenbit 4y agoIirc the Ring was made of 'scrith', which was probably Protector for what we now call unobtanium.
- BizarroLand 4y agoTo be fair, materials sciences are still advancing to this day, so even though no base element contains a measurable fragment of scrith's material properties, it's not entirely infeasible that no alloy in the universe could approach it.
- WalterBright 4y ago> The centrifugal forces would tear our apart. I'm not so sure about that. Consider slicing the ring into sections. If the ring is at the same radius and velocity of an object in orbit, then the slices will (mostly) stay put. They aren't going to fly off radially. So connecting them will not put undue stress on them. I say mostly because they'll be tugs from the other planets, etc.
- sliken 4y agoI think you are missing that the gravity comes from the centrifugal forces. Said gravity is for humans to be able to walk around, as well as keeping air and water from being lost to space. So sure you could make a non-spinning ring that minimizes the tension, velocity, and centrifugal force, but it would not provide a large living area like the ringworld does.
- WalterBright 4y agoYou're right, I missed that. Oops!
- jojobas 4y agoI don't get it. There should be 1g of centrifugal force. (This requires kilometers of atmospheric altitude to keep the air, but that's beside the point). What would tear us apart?
- consilient 4y agoHoop stress scales with the radius too, since there's more material pulling on itself. You're looking at many trillions of pascals for an Earth-equivalent ringworld.
- moloch-hai 4y agoWay, way more than that.
- sliken 4y ago
- sliken 4y agoSo maybe it would work with a red dwarf with much less gravity and brightness. As a bonus the star would last 10-1000 times longer.
- deleted 4y ago[deleted]